Dears, in addition to the comments of (brother), it is better to check the call preemption which drops the normal calls and gives priority to the VIP calls, here is important to know the source of calls from which kind of area it is?(much increment is in which kind of area(business, military, residential,….). to judge better. i know that the traffic has gone up in all your network but it cant be uniform increment in over all network. it is better to mention the source of call increment.